Politics. Diefenbaker had a conservative majority. Destroying everything made it much more difficult for a future Liberal government to restart the program.
Why would a future Liberal goverment restart it if the past one wanted to shut it down but didn't have the guts (or at least that's my understanding of the article)?
Ban / "Burn the books" does seem to fall on the 'conservative' side of the spectrum every time I can recall.
That is why Trump supporters are buying Teslas.
They are electric and have no trans.
That's only a funny joke if you dare to tell it right. Transmissions are called trannies.